If the operator is In or NotIn, the values array must be non-empty.
If the operator is Exists or DoesNotExist, the values array must be empty.
If the operator is Gt or Lt, the values array must have a single element, which will be interpreted as an integer.
This array is replaced during a strategic merge patch.
A node selector requirement is a selector that contains values, a key, and an operator that relates the key and values.